Transcatheter heart valve (THV) leaflet thrombosis in the neo-sinus and associated reduced leaflet motion is of clinical concern due to risks of embolism and worsened valve hemodynamics. Flow stasis in the neo-sinus (the space between the native and THV leaflets) is a known risk factor, but the role of proximal coronary flow is yet to be investigated. We tested two replicas of FDA approved commercial THVs-intra-annular and supra-annular (similar to the SAPIEN 3 and CoreValve families)-in a left heart simulator with coronary flow. Velocity fields in the left coronary cusp (LCC) and non (NCC) neo-sinus were quantified using high speed particle image velocimetry and particle residence times (PRT) were computed to evaluate flow stasis in the region. The supra-annular THV LCC neo-sinus had shorter PRT than its NCC neo-sinus (0.66 ± 0.00 vs. 0.76 ± 0.04, p = 0.038), while the intra-annular THV LCC neo-sinus had similar PRT to its NCC neo-sinus (1.93 ± 0.05 vs. 1.92 ± 0.03 cycles, p = 0.889). The supra-annular valve LCC and NCC neo-sinuses had shorter PRT than their intra-annular valve counterparts (p < 0.001). These results showed that coronary flow reduces flow stasis in the supra-annular THV neo-sinus and, ostensibly, thrombosis risk in the region. This effect was not significant in the intra-annular valve.
Keywords: Coronary flow; Flow Stasis; Neo-sinus; Particle image velocimetry; TAVR; Thrombosis.